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TI-2026-74362 Aliases CVE-2026-107348

Integer overflow in PgBouncer buffer growth causes infinite loop

Priority LOW 27CWE-190Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-190 and the CVSS impact.

Summary

PgBouncer from 1.21.0 before 1.26.1 is affected. An integer overflow in the message buffer growth logic (CWE-190) leaves a loop that never ends when max_packet_size is set above 2147483648. A remote attacker can send a packet header declaring a length above 2^31, and since 1.23.0 this works before authentication with a five-byte header. The single process then stalls all pooled connections until it is restarted.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

Integer overflow in the message buffer growth logic (mbuf_make_room) in PgBouncer 1.21.0 through 1.26.0 allows a remote attacker to cause a denial of service when max_packet_size is configured above 2147483648. A packet header declaring a length above 2^31 makes the buffer size computation overflow, leaving the growth loop unable to terminate. Because PgBouncer serves all clients from a single process, this saturates a CPU core and stalls every pooled connection until the process is restarted. Since 1.23.0 the overflow is reachable before authentication with a five-byte packet header.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00392 33rd percentileScored 2026-11-07
Fix Fixed PgBouncer: 1.26.1Red Hat: 1 advisory

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
—PgBouncer1.21.0 to before 1.26.11.26.1Patch availableCNA
  • PgBouncer Vendor— Affected 1.21.0 to before 1.26.1 Fixed in 1.26.1 Patch available CNA

Remediation

Upgrade PgBouncer to version 1.26.1. Red Hat fixes this for Red Hat Hardened Images in RHSA-2026:83843.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

  • Fix · CNA PgBouncer Fixed in 1.26.1

Red Hat 1 advisory

  • RHSA-2026:83843 Released 2026-10-16 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images pgbouncer-1.26.1-1.hum1@aarch64, pgbouncer-1.26.1-1.hum1@s390x, pgbouncer-1.26.1-1.hum1@src +1

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    PgBouncer 1.26.1

    3 records Highest priority Priority MEDIUM 1 MEDIUM, 2 LOW

    Other records, highest priority first

    • TI-2026-74364 PgBouncer authentication bypass lets attackers log in as other usersPriority MEDIUM 40
    • TI-2026-74363 Infinite loop in PgBouncer startup options parameter handlingPriority LOW 39
    Show all 3 records →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Hardened ImagesFixed RHSA-2026:83843

Timeline

  1. 2026-10-15 Threatist record created from CVE-2026-107348
  2. 2026-10-16 Priority changed: MEDIUM → LOW
  3. 2026-10-16 Affected versions changed · Red Hat
  4. 2026-10-16 CVSS score added · Red Hat
  5. 2026-10-18 CISA SSVC decision points changed
  6. 2026-10-18 Fix available: RHSA-2026:83843 · Red Hat
  7. 2026-10-18 Fix available: Red Hat Hardened Images · Red Hat

References

Other 1

Sources

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